Bush was celebrating his 88th birthday with family at his summer home in Maine, where two days earlier he got to fly via helicopter to the USS George H.W. Bush, the newest carrier in the Navy fleet and the only one whose namesake is alive.

Bush was a naval aviator during World War II. He enlisted on his 18th birthday following the attack on Pearl Harbor in 1941, postponing college for the opportunity to serve. His plane was shot down over the Pacific, but Bush survived.

“Do you feel like you used that second shot at life to the best?” his granddaughter asks.

“I’m sure I could have done a lot of things better,” he said. “It’s been a fulfilling time of my life, a lot of experiences, including being president of the United States.”

Bush recently traveled to Washington, D.C., for another family reunion of sorts at the White House. Fourteen members of the Bush family and hundreds of former Bush administration officials attended a ceremony to unveil the official presidential portrait of his son, George W. Bush.

“It was exciting,” he said. “Any time you go there, a certain sense of wonder about the experience. A lot of memories come flooding back. It’s hard to describe it.”

This week, HBO debuts a documentary about Bush, chronicling his life and his presidency, including his reflections on critical moments during his 4-year tenure such as the Iraqi War and the Tiananmen Square massacre.

While Bush’s son was a two-term president, the elder Bush was defeated in his 1992 re-election bid by Bill Clinton.

“Terrible feeling, awful feeling,’’ he said about losing. “I really wanted to win and worked hard. Later on, people said, ‘Well, he didn’t really care,’ which is crazy. I worked my heart out.”

Bush said in his Today show interview that he doesn’t have any expectations on what his legacy will be.

“I want somebody else to define the legacy,” he said. “I’ve kind of banned the use of the ‘L’ word, legacy word. “I think history will get it right, point out some of the things I did wrong and perhaps some of the things I did right.”